Move TODO from `handle_monitor_update_res` into `Channel`
[rust-lightning] / lightning / src / ln / channel.rs
index 1f17c4dbac2c95ec67fbb3ed239e100dbe117416..896c475049b4df56673dfa5e2c3ca7d45760e448 100644 (file)
@@ -35,7 +35,8 @@ use crate::chain::BestBlock;
 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, LowerBoundedFeeEstimator};
 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
 use crate::chain::transaction::{OutPoint, TransactionData};
-use crate::chain::keysinterface::{Sign, EntropySource, BaseSign, SignerProvider};
+use crate::chain::keysinterface::{WriteableEcdsaChannelSigner, EntropySource, ChannelSigner, SignerProvider, NodeSigner, Recipient};
+use crate::routing::gossip::NodeId;
 use crate::util::events::ClosureReason;
 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
 use crate::util::logger::Logger;
@@ -498,7 +499,7 @@ pub(crate) const EXPIRE_PREV_CONFIG_TICKS: usize = 5;
 //
 // Holder designates channel data owned for the benefice of the user client.
 // Counterparty designates channel data owned by the another channel participant entity.
-pub(super) struct Channel<Signer: Sign> {
+pub(super) struct Channel<Signer: ChannelSigner> {
        config: LegacyChannelConfig,
 
        // Track the previous `ChannelConfig` so that we can continue forwarding HTLCs that were
@@ -557,6 +558,11 @@ pub(super) struct Channel<Signer: Sign> {
        monitor_pending_channel_ready: bool,
        monitor_pending_revoke_and_ack: bool,
        monitor_pending_commitment_signed: bool,
+
+       // TODO: If a channel is drop'd, we don't know whether the `ChannelMonitor` is ultimately
+       // responsible for some of the HTLCs here or not - we don't know whether the update in question
+       // completed or not. We currently ignore these fields entirely when force-closing a channel,
+       // but need to handle this somehow or we run the risk of losing HTLCs!
        monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
        monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        monitor_pending_finalized_fulfills: Vec<HTLCSource>,
@@ -742,6 +748,12 @@ pub(super) struct Channel<Signer: Sign> {
        /// The unique identifier used to re-derive the private key material for the channel through
        /// [`SignerProvider::derive_channel_signer`].
        channel_keys_id: [u8; 32],
+
+       /// When we generate [`ChannelMonitorUpdate`]s to persist, they may not be persisted immediately.
+       /// If we then persist the [`channelmanager::ChannelManager`] and crash before the persistence
+       /// completes we still need to be able to complete the persistence. Thus, we have to keep a
+       /// copy of the [`ChannelMonitorUpdate`] here until it is complete.
+       pending_monitor_updates: Vec<ChannelMonitorUpdate>,
 }
 
 #[cfg(any(test, fuzzing))]
@@ -832,7 +844,7 @@ macro_rules! secp_check {
        };
 }
 
-impl<Signer: Sign> Channel<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
        /// Returns the value to use for `holder_max_htlc_value_in_flight_msat` as a percentage of the
        /// `channel_value_satoshis` in msat, set through
        /// [`ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel`]
@@ -1111,6 +1123,8 @@ impl<Signer: Sign> Channel<Signer> {
 
                        channel_type,
                        channel_keys_id,
+
+                       pending_monitor_updates: Vec::new(),
                })
        }
 
@@ -1457,6 +1471,8 @@ impl<Signer: Sign> Channel<Signer> {
 
                        channel_type,
                        channel_keys_id,
+
+                       pending_monitor_updates: Vec::new(),
                };
 
                Ok(chan)
@@ -2427,7 +2443,14 @@ impl<Signer: Sign> Channel<Signer> {
        /// Handles a channel_ready message from our peer. If we've already sent our channel_ready
        /// and the channel is now usable (and public), this may generate an announcement_signatures to
        /// reply with.
-       pub fn channel_ready<L: Deref>(&mut self, msg: &msgs::ChannelReady, node_pk: PublicKey, genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock, logger: &L) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError> where L::Target: Logger {
+       pub fn channel_ready<NS: Deref, L: Deref>(
+               &mut self, msg: &msgs::ChannelReady, node_signer: &NS, genesis_block_hash: BlockHash,
+               user_config: &UserConfig, best_block: &BestBlock, logger: &L
+       ) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError>
+       where
+               NS::Target: NodeSigner,
+               L::Target: Logger
+       {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        self.workaround_lnd_bug_4006 = Some(msg.clone());
                        return Err(ChannelError::Ignore("Peer sent channel_ready when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned()));
@@ -2481,7 +2504,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                log_info!(logger, "Received channel_ready from peer for channel {}", log_bytes!(self.channel_id()));
 
-               Ok(self.get_announcement_sigs(node_pk, genesis_block_hash, user_config, best_block.height(), logger))
+               Ok(self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger))
        }
 
        /// Returns transaction if there is pending funding transaction that is yet to broadcast
@@ -3785,7 +3808,14 @@ impl<Signer: Sign> Channel<Signer> {
        /// Indicates that the latest ChannelMonitor update has been committed by the client
        /// successfully and we should restore normal operation. Returns messages which should be sent
        /// to the remote side.
-       pub fn monitor_updating_restored<L: Deref>(&mut self, logger: &L, node_pk: PublicKey, genesis_block_hash: BlockHash, user_config: &UserConfig, best_block_height: u32) -> MonitorRestoreUpdates where L::Target: Logger {
+       pub fn monitor_updating_restored<L: Deref, NS: Deref>(
+               &mut self, logger: &L, node_signer: &NS, genesis_block_hash: BlockHash,
+               user_config: &UserConfig, best_block_height: u32
+       ) -> MonitorRestoreUpdates
+       where
+               L::Target: Logger,
+               NS::Target: NodeSigner
+       {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateInProgress as u32, ChannelState::MonitorUpdateInProgress as u32);
                self.channel_state &= !(ChannelState::MonitorUpdateInProgress as u32);
 
@@ -3820,7 +3850,7 @@ impl<Signer: Sign> Channel<Signer> {
                        })
                } else { None };
 
-               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, user_config, best_block_height, logger);
+               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block_height, logger);
 
                let mut accepted_htlcs = Vec::new();
                mem::swap(&mut accepted_htlcs, &mut self.monitor_pending_forwards);
@@ -3972,9 +4002,14 @@ impl<Signer: Sign> Channel<Signer> {
        /// `cargo doc --document-private-items`):
        /// [`super::channelmanager::ChannelManager::force_close_without_broadcasting_txn`] and
        /// [`super::channelmanager::ChannelManager::force_close_all_channels_without_broadcasting_txn`].
-       pub fn channel_reestablish<L: Deref>(&mut self, msg: &msgs::ChannelReestablish, logger: &L,
-               node_pk: PublicKey, genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock)
-       -> Result<ReestablishResponses, ChannelError> where L::Target: Logger {
+       pub fn channel_reestablish<L: Deref, NS: Deref>(
+               &mut self, msg: &msgs::ChannelReestablish, logger: &L, node_signer: &NS,
+               genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock
+       ) -> Result<ReestablishResponses, ChannelError>
+       where
+               L::Target: Logger,
+               NS::Target: NodeSigner
+       {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
                        // While BOLT 2 doesn't indicate explicitly we should error this channel here, it
                        // almost certainly indicates we are going to end up out-of-sync in some way, so we
@@ -4038,7 +4073,7 @@ impl<Signer: Sign> Channel<Signer> {
                        })
                } else { None };
 
-               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, user_config, best_block.height(), logger);
+               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger);
 
                if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
                        // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's.
@@ -4871,6 +4906,10 @@ impl<Signer: Sign> Channel<Signer> {
                (self.channel_state & ChannelState::MonitorUpdateInProgress as u32) != 0
        }
 
+       pub fn get_next_monitor_update(&self) -> Option<&ChannelMonitorUpdate> {
+               self.pending_monitor_updates.first()
+       }
+
        /// Returns true if funding_created was sent/received.
        pub fn is_funding_initiated(&self) -> bool {
                self.channel_state >= ChannelState::FundingSent as u32
@@ -5010,9 +5049,14 @@ impl<Signer: Sign> Channel<Signer> {
        /// When a transaction is confirmed, we check whether it is or spends the funding transaction
        /// In the first case, we store the confirmation height and calculating the short channel id.
        /// In the second, we simply return an Err indicating we need to be force-closed now.
-       pub fn transactions_confirmed<L: Deref>(&mut self, block_hash: &BlockHash, height: u32,
-               txdata: &TransactionData, genesis_block_hash: BlockHash, node_pk: PublicKey, user_config: &UserConfig, logger: &L)
-       -> Result<(Option<msgs::ChannelReady>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
+       pub fn transactions_confirmed<NS: Deref, L: Deref>(
+               &mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData,
+               genesis_block_hash: BlockHash, node_signer: &NS, user_config: &UserConfig, logger: &L
+       ) -> Result<(Option<msgs::ChannelReady>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+       where
+               NS::Target: NodeSigner,
+               L::Target: Logger
+       {
                if let Some(funding_txo) = self.get_funding_txo() {
                        for &(index_in_block, tx) in txdata.iter() {
                                // Check if the transaction is the expected funding transaction, and if it is,
@@ -5058,7 +5102,7 @@ impl<Signer: Sign> Channel<Signer> {
                                        // may have already happened for this block).
                                        if let Some(channel_ready) = self.check_get_channel_ready(height) {
                                                log_info!(logger, "Sending a channel_ready to our peer for channel {}", log_bytes!(self.channel_id));
-                                               let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, user_config, height, logger);
+                                               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger);
                                                return Ok((Some(channel_ready), announcement_sigs));
                                        }
                                }
@@ -5084,13 +5128,25 @@ impl<Signer: Sign> Channel<Signer> {
        ///
        /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
        /// back.
-       pub fn best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_block_hash: BlockHash, node_pk: PublicKey, user_config: UserConfig, logger: &L)
-       -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
-               self.do_best_block_updated(height, highest_header_time, Some((genesis_block_hash, node_pk, user_config)), logger)
+       pub fn best_block_updated<NS: Deref, L: Deref>(
+               &mut self, height: u32, highest_header_time: u32, genesis_block_hash: BlockHash,
+               node_signer: &NS, user_config: &UserConfig, logger: &L
+       ) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+       where
+               NS::Target: NodeSigner,
+               L::Target: Logger
+       {
+               self.do_best_block_updated(height, highest_header_time, Some((genesis_block_hash, node_signer, user_config)), logger)
        }
 
-       fn do_best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_node_pk: Option<(BlockHash, PublicKey, UserConfig)>, logger: &L)
-       -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
+       fn do_best_block_updated<NS: Deref, L: Deref>(
+               &mut self, height: u32, highest_header_time: u32,
+               genesis_node_signer: Option<(BlockHash, &NS, &UserConfig)>, logger: &L
+       ) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
+       where
+               NS::Target: NodeSigner,
+               L::Target: Logger
+       {
                let mut timed_out_htlcs = Vec::new();
                // This mirrors the check in ChannelManager::decode_update_add_htlc_onion, refusing to
                // forward an HTLC when our counterparty should almost certainly just fail it for expiring
@@ -5111,8 +5167,8 @@ impl<Signer: Sign> Channel<Signer> {
                self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time);
 
                if let Some(channel_ready) = self.check_get_channel_ready(height) {
-                       let announcement_sigs = if let Some((genesis_block_hash, node_pk, user_config)) = genesis_node_pk {
-                               self.get_announcement_sigs(node_pk, genesis_block_hash, &user_config, height, logger)
+                       let announcement_sigs = if let Some((genesis_block_hash, node_signer, user_config)) = genesis_node_signer {
+                               self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger)
                        } else { None };
                        log_info!(logger, "Sending a channel_ready to our peer for channel {}", log_bytes!(self.channel_id));
                        return Ok((Some(channel_ready), timed_out_htlcs, announcement_sigs));
@@ -5152,8 +5208,8 @@ impl<Signer: Sign> Channel<Signer> {
                        return Err(ClosureReason::FundingTimedOut);
                }
 
-               let announcement_sigs = if let Some((genesis_block_hash, node_pk, user_config)) = genesis_node_pk {
-                       self.get_announcement_sigs(node_pk, genesis_block_hash, &user_config, height, logger)
+               let announcement_sigs = if let Some((genesis_block_hash, node_signer, user_config)) = genesis_node_signer {
+                       self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger)
                } else { None };
                Ok((None, timed_out_htlcs, announcement_sigs))
        }
@@ -5170,7 +5226,7 @@ impl<Signer: Sign> Channel<Signer> {
                        // larger. If we don't know that time has moved forward, we can just set it to the last
                        // time we saw and it will be ignored.
                        let best_time = self.update_time_counter;
-                       match self.do_best_block_updated(reorg_height, best_time, None, logger) {
+                       match self.do_best_block_updated(reorg_height, best_time, None::<(BlockHash, &&NodeSigner, &UserConfig)>, logger) {
                                Ok((channel_ready, timed_out_htlcs, announcement_sigs)) => {
                                        assert!(channel_ready.is_none(), "We can't generate a funding with 0 confirmations?");
                                        assert!(timed_out_htlcs.is_empty(), "We can't have accepted HTLCs with a timeout before our funding confirmation?");
@@ -5370,7 +5426,9 @@ impl<Signer: Sign> Channel<Signer> {
        /// closing).
        ///
        /// This will only return ChannelError::Ignore upon failure.
-       fn get_channel_announcement(&self, node_id: PublicKey, chain_hash: BlockHash, user_config: &UserConfig) -> Result<msgs::UnsignedChannelAnnouncement, ChannelError> {
+       fn get_channel_announcement<NS: Deref>(
+               &self, node_signer: &NS, chain_hash: BlockHash, user_config: &UserConfig,
+       ) -> Result<msgs::UnsignedChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
                if !self.config.announced_channel {
                        return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned()));
                }
@@ -5378,24 +5436,33 @@ impl<Signer: Sign> Channel<Signer> {
                        return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement if the channel is not currently usable".to_owned()));
                }
 
-               let were_node_one = node_id.serialize()[..] < self.counterparty_node_id.serialize()[..];
+               let node_id = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node)
+                       .map_err(|_| ChannelError::Ignore("Failed to retrieve own public key".to_owned()))?);
+               let counterparty_node_id = NodeId::from_pubkey(&self.get_counterparty_node_id());
+               let were_node_one = node_id.as_slice() < counterparty_node_id.as_slice();
 
                let msg = msgs::UnsignedChannelAnnouncement {
                        features: channelmanager::provided_channel_features(&user_config),
                        chain_hash,
                        short_channel_id: self.get_short_channel_id().unwrap(),
-                       node_id_1: if were_node_one { node_id } else { self.get_counterparty_node_id() },
-                       node_id_2: if were_node_one { self.get_counterparty_node_id() } else { node_id },
-                       bitcoin_key_1: if were_node_one { self.get_holder_pubkeys().funding_pubkey } else { self.counterparty_funding_pubkey().clone() },
-                       bitcoin_key_2: if were_node_one { self.counterparty_funding_pubkey().clone() } else { self.get_holder_pubkeys().funding_pubkey },
+                       node_id_1: if were_node_one { node_id } else { counterparty_node_id },
+                       node_id_2: if were_node_one { counterparty_node_id } else { node_id },
+                       bitcoin_key_1: NodeId::from_pubkey(if were_node_one { &self.get_holder_pubkeys().funding_pubkey } else { self.counterparty_funding_pubkey() }),
+                       bitcoin_key_2: NodeId::from_pubkey(if were_node_one { self.counterparty_funding_pubkey() } else { &self.get_holder_pubkeys().funding_pubkey }),
                        excess_data: Vec::new(),
                };
 
                Ok(msg)
        }
 
-       fn get_announcement_sigs<L: Deref>(&mut self, node_pk: PublicKey, genesis_block_hash: BlockHash, user_config: &UserConfig, best_block_height: u32, logger: &L)
-       -> Option<msgs::AnnouncementSignatures> where L::Target: Logger {
+       fn get_announcement_sigs<NS: Deref, L: Deref>(
+               &mut self, node_signer: &NS, genesis_block_hash: BlockHash, user_config: &UserConfig,
+               best_block_height: u32, logger: &L
+       ) -> Option<msgs::AnnouncementSignatures>
+       where
+               NS::Target: NodeSigner,
+               L::Target: Logger
+       {
                if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
                        return None;
                }
@@ -5414,14 +5481,21 @@ impl<Signer: Sign> Channel<Signer> {
                }
 
                log_trace!(logger, "Creating an announcement_signatures message for channel {}", log_bytes!(self.channel_id()));
-               let announcement = match self.get_channel_announcement(node_pk, genesis_block_hash, user_config) {
+               let announcement = match self.get_channel_announcement(node_signer, genesis_block_hash, user_config) {
                        Ok(a) => a,
-                       Err(_) => {
-                               log_trace!(logger, "Cannot create an announcement_signatures as channel is not public.");
+                       Err(e) => {
+                               log_trace!(logger, "{:?}", e);
                                return None;
                        }
                };
-               let (our_node_sig, our_bitcoin_sig) = match self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx) {
+               let our_node_sig = match node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement)) {
+                       Err(_) => {
+                               log_error!(logger, "Failed to generate node signature for channel_announcement. Channel will not be announced!");
+                               return None;
+                       },
+                       Ok(v) => v
+               };
+               let our_bitcoin_sig = match self.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.secp_ctx) {
                        Err(_) => {
                                log_error!(logger, "Signer rejected channel_announcement signing. Channel will not be announced!");
                                return None;
@@ -5440,11 +5514,17 @@ impl<Signer: Sign> Channel<Signer> {
 
        /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are
        /// available.
-       fn sign_channel_announcement(&self, our_node_id: PublicKey, announcement: msgs::UnsignedChannelAnnouncement) -> Result<msgs::ChannelAnnouncement, ChannelError> {
+       fn sign_channel_announcement<NS: Deref>(
+               &self, node_signer: &NS, announcement: msgs::UnsignedChannelAnnouncement
+       ) -> Result<msgs::ChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
                if let Some((their_node_sig, their_bitcoin_sig)) = self.announcement_sigs {
-                       let were_node_one = announcement.node_id_1 == our_node_id;
+                       let our_node_key = NodeId::from_pubkey(&node_signer.get_node_id(Recipient::Node)
+                               .map_err(|_| ChannelError::Ignore("Signer failed to retrieve own public key".to_owned()))?);
+                       let were_node_one = announcement.node_id_1 == our_node_key;
 
-                       let (our_node_sig, our_bitcoin_sig) = self.holder_signer.sign_channel_announcement(&announcement, &self.secp_ctx)
+                       let our_node_sig = node_signer.sign_gossip_message(msgs::UnsignedGossipMessage::ChannelAnnouncement(&announcement))
+                               .map_err(|_| ChannelError::Ignore("Failed to generate node signature for channel_announcement".to_owned()))?;
+                       let our_bitcoin_sig = self.holder_signer.sign_channel_announcement_with_funding_key(&announcement, &self.secp_ctx)
                                .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?;
                        Ok(msgs::ChannelAnnouncement {
                                node_signature_1: if were_node_one { our_node_sig } else { their_node_sig },
@@ -5461,8 +5541,11 @@ impl<Signer: Sign> Channel<Signer> {
        /// Processes an incoming announcement_signatures message, providing a fully-signed
        /// channel_announcement message which we can broadcast and storing our counterparty's
        /// signatures for later reconstruction/rebroadcast of the channel_announcement.
-       pub fn announcement_signatures(&mut self, our_node_id: PublicKey, chain_hash: BlockHash, best_block_height: u32, msg: &msgs::AnnouncementSignatures, user_config: &UserConfig) -> Result<msgs::ChannelAnnouncement, ChannelError> {
-               let announcement = self.get_channel_announcement(our_node_id.clone(), chain_hash, user_config)?;
+       pub fn announcement_signatures<NS: Deref>(
+               &mut self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32,
+               msg: &msgs::AnnouncementSignatures, user_config: &UserConfig
+       ) -> Result<msgs::ChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
+               let announcement = self.get_channel_announcement(node_signer, chain_hash, user_config)?;
 
                let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);
 
@@ -5483,20 +5566,22 @@ impl<Signer: Sign> Channel<Signer> {
                                "Got announcement_signatures prior to the required six confirmations - we may not have received a block yet that our peer has".to_owned()));
                }
 
-               self.sign_channel_announcement(our_node_id, announcement)
+               self.sign_channel_announcement(node_signer, announcement)
        }
 
        /// Gets a signed channel_announcement for this channel, if we previously received an
        /// announcement_signatures from our counterparty.
-       pub fn get_signed_channel_announcement(&self, our_node_id: PublicKey, chain_hash: BlockHash, best_block_height: u32, user_config: &UserConfig) -> Option<msgs::ChannelAnnouncement> {
+       pub fn get_signed_channel_announcement<NS: Deref>(
+               &self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, user_config: &UserConfig
+       ) -> Option<msgs::ChannelAnnouncement> where NS::Target: NodeSigner {
                if self.funding_tx_confirmation_height == 0 || self.funding_tx_confirmation_height + 5 > best_block_height {
                        return None;
                }
-               let announcement = match self.get_channel_announcement(our_node_id.clone(), chain_hash, user_config) {
+               let announcement = match self.get_channel_announcement(node_signer, chain_hash, user_config) {
                        Ok(res) => res,
                        Err(_) => return None,
                };
-               match self.sign_channel_announcement(our_node_id, announcement) {
+               match self.sign_channel_announcement(node_signer, announcement) {
                        Ok(res) => Some(res),
                        Err(_) => None,
                }
@@ -5725,8 +5810,16 @@ impl<Signer: Sign> Channel<Signer> {
                Ok(Some(res))
        }
 
-       /// Only fails in case of bad keys
+       /// Only fails in case of signer rejection.
        fn send_commitment_no_status_check<L: Deref>(&mut self, logger: &L) -> Result<(msgs::CommitmentSigned, ChannelMonitorUpdate), ChannelError> where L::Target: Logger {
+               let monitor_update = self.build_commitment_no_status_check(logger);
+               match self.send_commitment_no_state_update(logger) {
+                       Ok((commitment_signed, _)) => Ok((commitment_signed, monitor_update)),
+                       Err(e) => Err(e),
+               }
+       }
+
+       fn build_commitment_no_status_check<L: Deref>(&mut self, logger: &L) -> ChannelMonitorUpdate where L::Target: Logger {
                log_trace!(logger, "Updating HTLC state for a newly-sent commitment_signed...");
                // We can upgrade the status of some HTLCs that are waiting on a commitment, even if we
                // fail to generate this, we still are at least at a position where upgrading their status
@@ -5759,15 +5852,9 @@ impl<Signer: Sign> Channel<Signer> {
                }
                self.resend_order = RAACommitmentOrder::RevokeAndACKFirst;
 
-               let (res, counterparty_commitment_txid, htlcs) = match self.send_commitment_no_state_update(logger) {
-                       Ok((res, (counterparty_commitment_tx, mut htlcs))) => {
-                               // Update state now that we've passed all the can-fail calls...
-                               let htlcs_no_ref: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)> =
-                                       htlcs.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect();
-                               (res, counterparty_commitment_tx, htlcs_no_ref)
-                       },
-                       Err(e) => return Err(e),
-               };
+               let (counterparty_commitment_txid, mut htlcs_ref) = self.build_commitment_no_state_update(logger);
+               let htlcs: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)> =
+                       htlcs_ref.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect();
 
                if self.announcement_sigs_state == AnnouncementSigsState::MessageSent {
                        self.announcement_sigs_state = AnnouncementSigsState::Committed;
@@ -5784,16 +5871,13 @@ impl<Signer: Sign> Channel<Signer> {
                        }]
                };
                self.channel_state |= ChannelState::AwaitingRemoteRevoke as u32;
-               Ok((res, monitor_update))
+               monitor_update
        }
 
-       /// Only fails in case of bad keys. Used for channel_reestablish commitment_signed generation
-       /// when we shouldn't change HTLC/channel state.
-       fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
+       fn build_commitment_no_state_update<L: Deref>(&self, logger: &L) -> (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) where L::Target: Logger {
                let counterparty_keys = self.build_remote_transaction_keys();
                let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
                let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
-               let (signature, htlc_signatures);
 
                #[cfg(any(test, fuzzing))]
                {
@@ -5813,6 +5897,21 @@ impl<Signer: Sign> Channel<Signer> {
                        }
                }
 
+               (counterparty_commitment_txid, commitment_stats.htlcs_included)
+       }
+
+       /// Only fails in case of signer rejection. Used for channel_reestablish commitment_signed
+       /// generation when we shouldn't change HTLC/channel state.
+       fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
+               // Get the fee tests from `build_commitment_no_state_update`
+               #[cfg(any(test, fuzzing))]
+               self.build_commitment_no_state_update(logger);
+
+               let counterparty_keys = self.build_remote_transaction_keys();
+               let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
+               let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
+               let (signature, htlc_signatures);
+
                {
                        let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len());
                        for &(ref htlc, _) in commitment_stats.htlcs_included.iter() {
@@ -6069,7 +6168,7 @@ impl Readable for AnnouncementSigsState {
        }
 }
 
-impl<Signer: Sign> Writeable for Channel<Signer> {
+impl<Signer: WriteableEcdsaChannelSigner> Writeable for Channel<Signer> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                // Note that we write out as if remove_uncommitted_htlcs_and_mark_paused had just been
                // called.
@@ -6811,6 +6910,8 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 
                        channel_type: channel_type.unwrap(),
                        channel_keys_id,
+
+                       pending_monitor_updates: Vec::new(),
                })
        }
 }
@@ -6837,22 +6938,19 @@ mod tests {
        use crate::ln::chan_utils::{htlc_success_tx_weight, htlc_timeout_tx_weight};
        use crate::chain::BestBlock;
        use crate::chain::chaininterface::{FeeEstimator, LowerBoundedFeeEstimator, ConfirmationTarget};
-       use crate::chain::keysinterface::{BaseSign, InMemorySigner, Recipient, KeyMaterial, EntropySource, NodeSigner, SignerProvider};
+       use crate::chain::keysinterface::{ChannelSigner, InMemorySigner, EntropySource, SignerProvider};
        use crate::chain::transaction::OutPoint;
        use crate::util::config::UserConfig;
        use crate::util::enforcing_trait_impls::EnforcingSigner;
        use crate::util::errors::APIError;
        use crate::util::test_utils;
        use crate::util::test_utils::OnGetShutdownScriptpubkey;
-       use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Scalar};
+       use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
        use bitcoin::secp256k1::ffi::Signature as FFISignature;
        use bitcoin::secp256k1::{SecretKey,PublicKey};
-       use bitcoin::secp256k1::ecdh::SharedSecret;
-       use bitcoin::secp256k1::ecdsa::RecoverableSignature;
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::Hash;
        use bitcoin::hash_types::WPubkeyHash;
-       use bitcoin::bech32::u5;
        use bitcoin::PackedLockTime;
        use bitcoin::util::address::WitnessVersion;
        use crate::prelude::*;
@@ -6891,21 +6989,6 @@ mod tests {
                fn get_secure_random_bytes(&self) -> [u8; 32] { [0; 32] }
        }
 
-       impl NodeSigner for Keys {
-               fn get_node_secret(&self, _recipient: Recipient) -> Result<SecretKey, ()> { panic!(); }
-
-               fn get_node_id(&self, recipient: Recipient) -> Result<PublicKey, ()> {
-                       let secp_ctx = Secp256k1::signing_only();
-                       Ok(PublicKey::from_secret_key(&secp_ctx, &self.get_node_secret(recipient)?))
-               }
-
-               fn ecdh(&self, _recipient: Recipient, _other_key: &PublicKey, _tweak: Option<&Scalar>) -> Result<SharedSecret, ()> { panic!(); }
-
-               fn get_inbound_payment_key_material(&self) -> KeyMaterial { panic!(); }
-
-               fn sign_invoice(&self, _hrp_bytes: &[u8], _invoice_data: &[u5], _recipient: Recipient) -> Result<RecoverableSignature, ()> { panic!(); }
-       }
-
        impl SignerProvider for Keys {
                type Signer = InMemorySigner;
 
@@ -7360,7 +7443,7 @@ mod tests {
                use bitcoin::hashes::hex::FromHex;
                use bitcoin::hash_types::Txid;
                use bitcoin::secp256k1::Message;
-               use crate::chain::keysinterface::BaseSign;
+               use crate::chain::keysinterface::EcdsaChannelSigner;
                use crate::ln::PaymentPreimage;
                use crate::ln::channel::{HTLCOutputInCommitment ,TxCreationKeys};
                use crate::ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
@@ -7374,7 +7457,6 @@ mod tests {
 
                let mut signer = InMemorySigner::new(
                        &secp_ctx,
-                       SecretKey::from_slice(&hex::decode("4242424242424242424242424242424242424242424242424242424242424242").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),